In one embodiment disclosed herein, the specific subsequent physical process includes slicing the product into individual slices on a slicing machine. Such slicing machines are principally, but not exclusively, used for slicing food products such as cheese, meat and pressed or molded meat products.
Food articles can be sliced on high speed slicing machines such as disclosed in U.S. Pat. Nos. 5,628,237 or 5,974,925 or as commercially available as the FX180® slicer available from Formax, Inc. of Mokena, Ill., USA. Food articles can also be sliced on high speed slicing machines such as disclosed in U.S. patent application Ser. No. 12/255,623, or as commercially available as the PowerMax4000™ slicing system available from Formax, Inc. U.S. Pat. Nos. 5,628,237 or 5,974,925 and U.S. Published Application US2009/0151527 are each hereby incorporated by reference except where inconsistent with the present disclosure.
Typically such slicing machines include a rotating blade and a product feeder that drives the product forward towards the blade so that successive slices are cut from one face of the product. The distance through which the product is advanced between successive cuts of the blade determines the thickness of the slices. Where the product is of uniform shape and density, it may be sufficient to use a single predetermined slice thickness to give a slice or group of slices of the required weight. Further, it may be sufficient to provide an output scale proximate the output side of the blade to measure the current weight of the slice to product and adjust the thickness of the subsequent slice(s) to make the desired unit weight.
In general, however, variations in the shape and density of the product mean that the weight of a slice of a given thickness varies. A previous approach to dealing with this variation is described in U.S. Pat. No. 4,428,263, which is hereby incorporated by reference. That patent describes a process in which an automatic slicing machine is programmed to vary the thickness of the slices in accordance with a typical weight distribution for the product.
It has also been proposed to make some determination of the cross-sectional area of the product as it is cut. One such system is purportedly disclosed in U.S. Pat. No. 5,136,906, titled “Slicing Machine”, and assigned to Thurne Engineering Co., Ltd. According to that patent, a slicing machine for cutting slices from a product includes a camera arranged to view a cut face of the product, boundary recognition apparatus arranged to process image signals from the camera to determine a boundary of the cut face, calculating apparatus arranged to calculate a parameter characteristic of the cut face from image data corresponding to regions of the cut face within the boundary, and control signal generating apparatus arranged to generate a control signal to control the operation of the slicer in accordance with the determined parameter.
Although the foregoing system may be suitable for low-throughput slicing machines, it is significantly less suitable for high-speed slicing machines, such as those available from Formax, Inc., of Mokena, Ill., under the brand names FX-180® or PowerMax4000™. First, by calculating the product profile at the cut face, a very limited amount of processing time is available to perform the calculations that are necessary to ensure the proper thickness of each slice before the cut face must again be imaged for processing the thickness of the next slice. Second, substantial measurement inaccuracies may result from shadowing effects resulting from the relative positions of the illumination source, cut face, and slicing machine components—a problem not addressed in the '906 patent. Third, further measurement inaccuracies are introduced by the apparent assumption that the profiles at the bottom and a side of the product are linear. Finally, by attempting to measure the product profile at the cut face, substantial inaccuracies may be introduced due to the presence of scrap product. One of the goals of the apparatus described in the '906 patent is to remove the inaccuracies introduced by the scrap product. However, by addressing this problem at the cut face, the apparatus of the '906 must necessarily introduce a further level and higher degree of image processing.
FIG. 1 illustrates a prior art product processing system described more completely in U.S. Pat. No. 7,450,247, herein incorporated by reference. The system is shown generally at 10, and performs a physical process on a product in which the physical process is dependent on accurate measurement of the profile of the raw product, such as a slab or carcass of meat. As shown, product processing system 10 is comprised of a product profiling apparatus 15 and a product processor 20. The product profiling apparatus 15 functions to measure the profile of the raw product and provide the profile information to the product processor 20 that, in turn, uses the information to accurately execute the physical process that is to be performed on the raw product.
In the embodiment illustrated in FIG. 1, the acquisition of the product profile information is completed before the particular raw product undergoes physical processing in the product processor 20. Using the configuration shown in FIG. 1 in which the profiling apparatus 15 is disposed prior to the product processor 20, it is possible to acquire complete product profiles for several individual raw products before each of the raw products is provided to the input of the product processor 20. Additionally, if the profiling apparatus 15 is designed as a stand-alone apparatus, then the profiling apparatus 15 may be used to provide product profile information to a plurality of different product processors that are operating in either a time sequential or concurrent manner.
Generally stated, the profiling apparatus 15 is comprised of an input section 25, a scanning section 30, and an output section 35. The input section 25 includes a conveying surface 40 disposed to support the product 45 that is to be profiled.
Scanning section 30 includes a housing 55 having an input end that is open to receive product 45 and an outlet end that is open to allow product 45 to exit therefrom. In the illustrated embodiment, housing 55 comprises a principal housing portion 60, an upper vision system housing 65, and a lower vision housing 70. The upper vision system housing 65 includes an upper vision system disposed therein. The upper vision system of the disclosed embodiment includes a vertically directed line laser 75 for illuminating one side of the product in a fixed plane traversed by the driven product and an associated camera 80 vertically angled for imaging the laser-illuminated contour of the product 45. Similarly, the lower vision system housing 70 includes a lower vision system disposed therein that is comprised of a line laser 85 and corresponding camera 90 for addressing the other side of the product. Each of the upper and lower vision system housings 65 and 70 includes an opening that is positioned to allow the respective vision system to view a product 45 passing through the principal housing 60. These openings may merely comprise cut out sections. Preferably, however, the openings are covered with a transparent material to form a window that mechanically isolates the vision system components from the components disposed in the principal housing 60 yet does not interfere with the vision system operation. While the prior art system of FIG. 1 is capable of obtaining a product profile, there exists a need for a product profiling system that obtains profile information with more precision.
The present inventors have addressed many of the foregoing problems inherent in the product profiling operations of prior art. To this end, they have developed an accurate and cost-effective product profiling apparatus that is suitable for use, for example, in connection with high-speed product slicing machines.
Numerous other advantages and features of the present invention will be become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings.